Place the carrot and swede in a large saucepan and cover with water.
Add a pinch of salt.
Place the pan on the hob over medium heat and bring to a simmer.
Reduce the heat if necessary.
Simmer for 20-30 minutes until the swede is soft.
Drain thoroughly and return to the saucepan.
Return the saucepan to the hob over very low heat.
Toss thoroughly for 2-3 minutes to remove any water.
Remove the veg from the pan and set to one side.
Add the butter to the same pan with a pinch of salt and pepper and a small splash of milk.
Melt the butter over low heat, stirring often.
Remove from the heat.
Carefully tip the drained swede and carrots into the pan with the melted butter.
Mash thoroughly or whizz with a stick blender until smooth, adding a little more milk if needed.
Notes
I’ve listed 400g of carrot and swede, but as long as they are even, it doesn’t really matter. Weigh your peeled swede and match it with carrots. If you have more or less, remember to adjust the butter and milk, too.